The present disclosure relates to an organic rankine cycle (ORC) system. More particularly, the present disclosure relates to an improved method and system for recovering oil from an evaporator of an ORC system.
Rankine cycle systems are commonly used for generating electrical power. The rankine cycle system includes an evaporator or a boiler for evaporation of a motive fluid, a turbine that receives the vapor from the evaporator to drive a generator, a condenser for condensing the vapor, and a pump or other means for recycling the condensed fluid to the evaporator. The motive fluid in rankine cycle systems is often water, and the turbine is thus driven by steam. An organic rankine cycle (ORC) system operates similarly to a traditional rankine cycle, except that an ORC system uses an organic fluid, instead of water, as the motive fluid.
Oil may be used for lubrication in the ORC system, particularly inside the turbine. For example, oil provides lubrication for the bearings of the turbine. During operation of the ORC system, the oil may migrate from the turbine to other areas of the system. The oil may travel, with the refrigerant, from the turbine to the condenser and then to the evaporator. In some cases, it may be difficult to recover the oil from the evaporator, which results in a decrease in an amount of oil available for operation of the turbine.
There is a need for a method and system for recovering the oil from the evaporator of the ORC system and delivering it back to the turbine.